Who is Khan Abdul Ghaffar Khan from Gandhi, the Man and what is their importance?

Khan Abdul Ghaffar Khan was a Pathan Muslim who came to be known as the Frontier Gandhi, having forsaken his tribe's violence and mindset of revenge for Gandhi's philosophy of returning love for hatred and formed an army called the Khudai Khidmatgars. They would defend the wild and mysterious Frontier from Britain's brutal military governance.